Question 43339
3^(2x+2)-18(3^x)+9=0

(3^2x)(3^2) -18(3^x) +9=0
Factor out the "9" to get:

3^2x-2(3^x)+1=0

This is a quadratic equation.

Let w=3^x

You get:
w^2-2w+1=0
(w-1)^2=0

Therefore:
(3^x-1)^2=0
3^x=1
x=0

Cheers,
Stan H.